亚硝基芳族自旋捕集剂3,5-二溴-4-亚硝基苯磺酸钠盐（DBNBS）在水溶液中的单体-二聚体平衡。

Monomer-dimer equilibrium of nitroso-aromatic spin trap 3,5-dibromo-4-nitrosobenzenesulfonic acid, sodium salt (DBNBS), in aqueous solution.

作者信息

Ide H, Hagi A, Ohsumi S, Murakami A, Makino K

机构信息

Department of Polymer Science and Engineering, Kyoto Institute of Technology, Japan.

出版信息

Biochem Int. 1992 Jul;27(3):367-72.

PMID:1417874

Abstract

3,5-Dibromo-4-nitrosobenzenesulfonic acid, sodium salt (DBNBS), which is widely used as a spin trap in biological systems, was allowed to form the monomer-dimer equilibrium in aqueous solution, and its equilibrium constant (Kc) was determined by NMR measurement and visible spectrum analysis. The Kc values obtained from the two different methods were virtually identical and evaluated as 1.3 x 10(-3) mol dm-3 at 25 degrees C. Further, the molar extinction coefficient of DBNBS monomer (epsilon 760) was determined to be 34 dm3mol-1cm-1. The present results indicate that only a minor portion (ca. 20%) of dissolved DBNBS (10 mmol dm-3) is practically capable of spin trapping under the conditions most widely used in biological studies.

摘要

3,5-二溴-4-亚硝基苯磺酸的钠盐（DBNBS）在生物体系中广泛用作自旋捕捉剂，它在水溶液中形成单体-二聚体平衡，其平衡常数（Kc）通过核磁共振测量和可见光谱分析来测定。从两种不同方法得到的Kc值实际上是相同的，在25℃时评估为1.3×10⁻³ mol dm⁻³。此外，DBNBS单体的摩尔消光系数（ε760）测定为34 dm³mol⁻¹cm⁻¹。目前的结果表明，在生物研究中最广泛使用的条件下，溶解的DBNBS（10 mmol dm⁻³）实际上只有一小部分（约20%）能够进行自旋捕捉。